It is now well known that certain materials exhibit exceptional electrical conductive properties which have earned them the distinctive designation of superconductors. Though many superconductor materials are known, ways in which superconductor materials can be incorporated into commercially viable products are not so well known. Indeed, in recent years, extensive efforts have been made to solve many of the problems which confront the manufacturers of superconductor products
One particular class of superconductor materials which has attracted a great deal of interest for its potential use in commercial products is the so-called 1-2-3 materials that include rare earth elements (RE) and are from the group identified as RE Ba.sub.2 Cu.sub.3 O.sub.7-x. For commercial purposes, it has been determined that these materials are particularly effective in a ceramic form which is made by sintering very fine crystalline particles of 1-2-3. Of importance to the present invention is the fact that, due primarily to properties of the rare earth elements in the particular crystalline structure of these 1-2-3 particles, they can be effectively influenced by a magnetic field before they are sintered. Importantly, it is desirable that the superconductor particles have animotropic magnetic susceptibilities. Further, since the par can also be charged before they are sintered, they can also be influenced by an electric field.
With the above in mind, one problem which has heretofore confronted persons skilled in the superconductor art concerns how to support the inherently brittle superconductor ceramic. An obvious solution is to use some form of a supporting substrate. Though substrates of various forms may be used, for certain applications a substrate in the form of a fiber, a wire or a ribbon is ideal. Unfortunately, effectively placing a superconductor ceramic on such a substrate is not easy. For one thing, the ceramic needs to be directly attached to the substrate. Furthermore, the superconductor layer should preferably be of uniform thickness and relatively thin. The present invention recognizes that one way in which to use these substrates is to deposit a thin layer of very fine particles of 1-2-3 on the substrate before they are sintered into a ceramic.
Electrophoresis is a well known process for coating metal substrates which involves the motion of colloidal particles suspended in a fluid medium due to the influence of an electric field on the medium. Although some superconductor materials are not adversely affected by water, unfortunately, the 1-2-3 material deteriorates when exposed to moisture. Thus, when 1-2-3 superconductor materials are used, the fluid mediums typically used for electrophoresis, which include water, can not be used in a procedure to coat a metal substrate with fine superconductor particles. The present invention, however, recognizes that an electrophoresis procedure can be accomplished using a nonaqueous solution as the fluid medium. Further, the present invention recognizes that a magnetic field will affect the superconductor particles in the medium to align them on the substrate in an optimal orientation.
In light of the above, it is an object of the present invention to provide an apparatus for attaching superconductor particles to a metal substrate. Another object of the present invention is to provide an apparatus which uses a nonaqueous fluid medium in an electrophoresis procedure to coat a metallic substrate with superconductor particles. Yet another object of the present invention is to provide an apparatus which magnetically aligns superconductor particles in a desired orientation on a metallic substrate during the coating process. Still another object of the present invention is to provide a method for coating a metal substrate with magnetically aligned superconductor particles. Another object of the present invention is to provide an apparatus for coating metallic substrates that is relatively easy to manufacture, relatively simple to operate and cost effective.